content: /*
   * Copyright 2016-present David Karnok
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package hu.akarnokd.rxjava3.joins;
  
  import java.util.*;
  import java.util.concurrent.atomic.AtomicReference;
  
  import io.reactivex.rxjava3.core.Observer;
  import io.reactivex.rxjava3.functions.*;
  
  /**
   * Represents an execution plan for join patterns.
   * @param <R> the result type
   */
  final class PlanN<R> extends Plan<R> {
      protected final PatternN expression;
      protected final Function<? super Object[], R> selector;
  
      PlanN(PatternN expression, Function<? super Object[], R> selector) {
          this.expression = expression;
          this.selector = selector;
      }
  
      @Override
      public ActivePlan0 activate(Map<Object, JoinObserver> externalSubscriptions,
              final Observer<R> observer, final Consumer<ActivePlan0> deactivate) {
          Consumer<Throwable> onError = onErrorFrom(observer);
  
          final List<JoinObserver1<? extends Object>> observers = new ArrayList<>();
          for (int i = 0; i < expression.size(); i++) {
              observers.add(createObserver(externalSubscriptions, expression.get(i), onError));
          }
          final AtomicReference<ActivePlanN> self = new AtomicReference<>();
  
          ActivePlanN activePlan = new ActivePlanN(observers, new Consumer<Object[]>() {
                      @Override
                      public void accept(Object[]args) {
                          R result;
                          try {
                              result = selector.apply(args);
                          } catch (Throwable t) {
                              observer.onError(t);
                              return;
                          }
                          observer.onNext(result);
                      }
                  },
                  new Action() {
                      @Override
                      public void run() throws Throwable {
                          for (JoinObserver1<? extends Object> jo : observers) {
                              jo.removeActivePlan(self.get());
                          }
                          deactivate.accept(self.get());
                      }
                  });
  
          self.set(activePlan);
  
          for (JoinObserver1<? extends Object> jo : observers) {
              jo.addActivePlan(activePlan);
          }
  
          return activePlan;
      }
  
  }
  